This invention relates to a radiation sensitive resin composition, and more particularly, to a radiation sensitive resin composition suitable as a negative type resist for preparing an integrated circuit sensitive to radiations such as ultraviolet rays, deep ultraviolet rays, X rays, electron beams, molecular beams, .gamma. rays, synchrotron radiations, proton beams and the like.
In the field of fine processing, a representative of which is the production of an integrated circuit element, a lithographic process enabling fine processing of 0.5 .mu.m or less is now being developed in order to obtain a higher integration degree. Simultaneously therewith, there has recently been increased the demand of a resist excellent in thermal resistance, resistance to ion beams and the like which resist is used in the form of a thick film in a high-energy ion implantation processing.
Conventional typical resists which have been used in the lithographic process are negative type resists using a cyclized rubber and a bisazide compound and positive type resists using a novolak resin and a quinonediazide compound.
However, the performance of each of the above resists approaches its limit, and a difficulty accompanies the use of the resist in the fine processing of 0.5 .mu.m or less.
For example, in the negative type resist, fine patterns contact one another owing to the swelling of the resist during development. Also, when the positive type resist is irradiated with deep ultraviolet rays, the absorption of the rays by the resist is too strong and the sectional shape of the pattern becomes a triangle. When the positive type resist is irradiated with a high energy radiation such as electron beam or X rays the resist is cured to be converted into a negative type. Accordingly, it has been difficult to obtain a suitable fine pattern.
Also, all the above resists have low thermal resistance at high temperatures of 150.degree. C. or more and are not suitable for use in the high-energy ion implantation processing.